From: "Lambrecht Jürgen" <J.Lambrecht@TELEVIC.com>
To: Florian Fainelli <florian@openwrt.org>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-embedded@vger.kernel.org" <linux-embedded@vger.kernel.org>
Subject: Re: [PATCH] net: phy: Add config option to specify external switch port to be used if switch is used as PHY
Date: Thu, 8 Sep 2011 12:00:13 +0200 [thread overview]
Message-ID: <4E68922D.8020805@televic.com> (raw)
In-Reply-To: <201109081039.35272.florian@openwrt.org>
On 09/08/2011 10:39 AM, Florian Fainelli wrote:
>
> Hello Jurgen,
>
> On Thursday 08 September 2011 08:54:07 Lambrecht J
WARNING: multiple messages have this Message-ID (diff)
From: "Lambrecht Jürgen" <J.Lambrecht@TELEVIC.com>
To: Florian Fainelli <florian@openwrt.org>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-embedded@vger.kernel.org" <linux-embedded@vger.kernel.org>
Subject: Re: [PATCH] net: phy: Add config option to specify external switch port to be used if switch is used as PHY
Date: Thu, 8 Sep 2011 12:00:13 +0200 [thread overview]
Message-ID: <4E68922D.8020805@televic.com> (raw)
In-Reply-To: <201109081039.35272.florian@openwrt.org>
On 09/08/2011 10:39 AM, Florian Fainelli wrote:
>
> Hello Jurgen,
>
> On Thursday 08 September 2011 08:54:07 Lambrecht Jürgen wrote:
> > Hello,
> >
> > In our embedded designs, this is a useful patch. Maybe it can be useful
> > for somebody else too.
> > Or maybe there are already better solutions?
> > I know I could also write a driver for our switch, but that is too much
> > effort just to select the active port.
>
> This is not going to work well with all switches out there. You could
> use the
>
Do not all switches follow the basic MII register map with room for 31
phy's?
>
> fixed-PHY driver to make your ethernet driver see the link as always
> up between
> the MAC and switch CPU port.
>
Indeed, I tried to, but it didn't work. (would be my preferred solution)
I juist enabled FIXED_PHY in menuconfig (and kept MII, NET_ETHERNET and
FEC (for my iMX cpu); also PHYLIB is on that makes mdio_bus.c compile).
I checked the architecture file for mpc866ads and didn't find any init
for it, but maybe I need to initialize fixed-PHY somewhere?
However, it could be interesting sometimes from application side to know
if the real external link is up, then fixed-PHY is not ok.
>
>
> A better solution would be to have proper switch drivers and
> user-space, which
> reminds me that we (OpenWrt) should at some point propose our switch
> drivers
> [1] for review.
>
> [1]:
> https://dev.openwrt.org/browser/trunk/target/linux/generic/files/drivers/net/phy/
>
Just had a fast look to the Marvell switch driver. Nice to know it is there.
>
>
> >
> > Kind regards,
> > Jürgen
> >
> > In embedded design, instead of a PHY, sometimes a switch is used that
> > behaves as a PHY through its MII port. For example to use a
> > daisy chain network configuration instead of an expensive star
> config. In
> > that case, many phy ports are available, but only 1 should be used
> > to check link status, and not the first one available as is
> > the case
> > without this configuration (that is, set to its default value
> > 0). So this options specifies the switch port number to be used to check
> > link status, because if the link is down, no data is sent
> by the
> > TCP/IP stack.
> >
> > Signed-off-by: Jürgen Lambrecht <J.Lambrecht@televic.com>
> > ---
>
[snip]
>
> --
> Florian
>
--
Jürgen Lambrecht
R&D Associate
Tel: +32 (0)51 303045 Fax: +32 (0)51 310670
http://www.televic-rail.com
Televic Rail NV - Leo Bekaertlaan 1 - 8870 Izegem - Belgium
Company number 0825.539.581 - RPR Kortrijk
next prev parent reply other threads:[~2011-09-08 10:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-08 6:54 [PATCH] net: phy: Add config option to specify external switch port to be used if switch is used as PHY Lambrecht Jürgen
2011-09-08 8:39 ` Florian Fainelli
2011-09-08 8:39 ` Florian Fainelli
2011-09-08 10:00 ` Lambrecht Jürgen [this message]
2011-09-08 10:00 ` Lambrecht Jürgen
2011-09-08 10:13 ` Francois Romieu
2011-09-08 10:13 ` Francois Romieu
2011-09-08 11:59 ` Lambrecht Jürgen
2011-09-08 21:24 ` Francois Romieu
2011-09-08 21:24 ` Francois Romieu
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